Forum Thread: Why on Some Networks a Simple db_nmap or a Normal Nmap Not Add Any Hosts in Msf or Armitage?

I was kind of wondering why no hosts would show up since metasploit v4.11.5 came out. This is troubling to me since before I updated, i could get every host that was mapped. After, on the same network, there are only two left. (Linux 2.6.x, embedded) After i do {nmap -sn 192.168.0.1/24} everything is listed with 6 hosts, but msf only adds two of them. How can i fix, workaround, or understand this?